The present disclosure relates a method for production of a solid-state imaging element, a solid-state imaging element, and an imaging apparatus equipped with said solid-state imaging element.
The recent trend in the field of CMOS (Complementary Metal Oxide Semiconductor) image sensor is toward multiplication of pixels and size reduction of pixels. Unfortunately, the size reduction of pixels is accompanied by a remarkable deterioration of pixel characteristics.
There has been proposed an idea of ion-implantation into individual pixels for the purpose of maintaining or improving such pixel characteristics as saturation charge amount (Qs), charge transfer, white spots, and sensitivity. (See Japanese Patent Laid-open No. 2005-223134, Japanese Patent Laid-open No. 2002-373978, Japanese Patent Laid-open No. 2004-273913, hereinafter referred to as Patent Documents 1 to 3, for example.)
The ion implantation into pixels adds new impurity regions to the existing structure, thereby controlling the potential distribution and improving the pixel characteristics.
The proposed way for improvement adds new impurity regions and hence makes the pixel structure more complex. This increases the number of fabricating steps and raises the production cost, which leads to a cost increase of image sensor chips.